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Droughts are increasingly frequent as the Earth warms, presenting adaptation challenges for ecosystems and human communities worldwide. A strategic environmental assessment (SEA) and the integration of adaptation strategies into policies, plans, and programs (PPP) are two important approaches for enhancing climate resilience and fostering sustainable development. This study developed an innovative approach to strengthen the SEA of droughts by quantifying the impacts of future temperature increases. A novel method for projecting drought events was integrated into the SEA process by leveraging multiple data sources, including atmospheric reanalysis, reconstructions, satellite-based observations, and model simulations. We identified drought conditions using terrestrial water storage (TWS) anomalies and applied a random forest (RF) model for disentangling the drivers behind drought events. We then set two global warming targets (2.0 °C and 2.5 °C) and analyzed drought changes under three shared socioeconomic pathways (SSP126, SSP370, SSP585). In a 2.0 °C warming world, over 50 % of the global surface will face increased drought risk. With an additional 0.5 °C increase, >60 % of the land will be prone to further drought escalation. We utilized copulas to build the joint distribution for drought duration and severity, estimating the joint return periods (JRP) for bivariate drought hazard. In tropical and subtropical regions, JRP reductions exceeding half are projected for >33 % of the regional land surface under 2.0 °C warming and for >50 % under 2.5 °C warming. Finally, we projected the impacts of drought events on population and gross domestic product (GDP). Among the three SSPs, under SSP370, population exposure is highest and GDP exposure is minimal under 2.0 °C warming. Global GDP and population risks from drought are projected to increase by 37 % and 24 %, respectively, as warming continues. This study enhances the accuracy of SEA in addressing drought risks and vulnerabilities, supporting climate-resilient planning and adaptive strategies.
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Many evidences have shown that both atmospheric and soil droughts can constrain vegetation growth and further threaten its ability to sequester carbon. However, the trigger thresholds of vegetation production loss under different atmospheric and soil drought conditions are still unknown. In this study, we proposed a Copula and Bayesian equations-based framework to investigate trigger thresholds of various vegetation production losses under different atmospheric and soil drought conditions. The trigger thresholds dynamics and their possible causes were also investigated. To achieve this goal, we first simulated the gross primary production, soil moisture, and vapor pressure deficit over China during 1961-2018 using an individual-based, spatially explicit dynamic global vegetation model. The main drivers of the dynamic change in trigger thresholds were then explored by Random Forest model. We found that soil drought caused greater stress on gross primary production loss than atmospheric drought, with a larger impact area and higher probability of damage. In terms of spatial distribution, the risk probability of gross primary production loss was higher in eastern China than in western China, and the drought trigger threshold was also smaller in eastern China. In addition, the trigger thresholds for atmospheric and soil drought in most regions exhibited a decreasing trend from 1961 to 2018, while the CO2 fertilization enhanced the drought tolerance of vegetation. The reduction in CO2 fertilization effect slowed down the downward trend of trigger threshold for soil drought, while the increase in temperature exacerbated the downward trend of trigger threshold for atmospheric drought. This study highlighted the larger effect of soil drought on vegetation production loss than atmospheric drought and implied that climate change can modulate the trigger threshold of vegetation production losses under drought conditions. These findings provide scientific guidance for managing the increasing risk of drought on vegetation and optimizing watershed water allocation.
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Flash droughts characterized by rapid onset and intensification are expected to be a new normal under climate change and potentially affect vegetation photosynthesis and terrestrial carbon sink. However, the effects of flash drought on vegetation photosynthesis and their potential dominant driving factors remain uncertain. Here, we quantify the susceptibility and response magnitude of vegetation photosynthesis to flash drought across different ecosystems (i.e., forest, shrubland, grassland, and cropland) in China based on reanalysis and satellite observations. By employing the extreme gradient boosting model, we also identify the dominant factors that influence these flash drought-photosynthesis relationships. We show that over 51.46 % of ecosystems across China are susceptible to flash drought, and grasslands are substantially suppressed, as reflected in both sensitivity and response magnitude (with median gross primary productivity anomalies of -0.13). We further demonstrate that background climate differences (e.g., mean annual temperature and aridity) predominantly regulate the response variation in forest and shrubland, with hotter/colder or drier ecosystems being more severely suppressed by flash drought. However, in grasslands and croplands, the differential vegetation responses are attributed to the intensity of abnormal hydro-meteorological conditions during flash drought (e.g., vapor pressure deficit (VPD) and temperature anomalies). The effects of flash droughts intensify with increasing VPD and nonmonotonically relate to temperature, with colder or hotter temperatures leading to more severe vegetation loss. Our results identify the vulnerable ecological regions under flash drought and enable a better understanding of vegetation photosynthesis response to climate extremes, which may be useful for developing effective management strategies.
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Mudança Climática , Secas , Ecossistema , Fotossíntese , China , FlorestasRESUMO
Climate change has a discernible influence on rainfall patterns, thus potentially affecting the intricate dynamics of soil respiration (Rs) and soil carbon storage. However, we still lack a profound understanding of the determinants of Rs response to rainfall events. Here, utilizing a comprehensive 10-year dataset (2004-2013), we explored the direction and magnitude of Rs response to rainfall events and the underlying determinants in a temperate forest. Based on the identified 368 rainfall events over the study period, we demonstrate that rainfall suppresses Rs when the soil moisture is optimal and moist in the growing season, whereas its effect on Rs during the non-growing season is minimal. Notably, antecedent soil moisture, rather than rainfall amount, shows a substantial impact on Rs during the growing season (coefficient of determination (R2) = 0.37 for antecedent soil moisture, and R2 < 0.01 for rainfall amount). Incorporating antecedent soil moisture significantly enhances the explanatory power (R2) from 0.09 to 0.45 regarding the relative changes in Rs following rainfall events. Our results highlight the environmental dependency of Rs response to rainfall events and suggest that incorporating the role of antecedent soil moisture could enhance predictability and reduce uncertainty in ecosystem modeling.
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It remains uncertain whether a protective association between physical activity and depression exists among adolescents and what the optimal level of physical activity might be. This study aimed to estimate the associations of physical activity levels with depressive symptoms and new-onset depression, while identifying potential modifying factors influencing the relationships. In this cohort study, we initially enrolled 1957 participants at baseline and followed up with 1738 of them after two years. Our analysis focused on data from 1482 students who provided complete information on both physical activity and depressive symptoms. Generalized linear regression and restricted cubic spline regression models were performed. Our adjusted models revealed that engaging in 4-7 h/week of moderate-to-vigorous physical activity (MVPA) at baseline was negatively associated with subsequent depressive symptoms and new-onset depression compared to the non-MVPA group. However, exceeding 7 h/week of MVPA did not provide substantial benefits. Furthermore, drinking and screen time potentially modified the relationship between MVPA and new-onset depression. Our findings suggest that 4-7 h of MVPA per week may be an appropriate level to reduce depressive symptoms in adolescents. Moreover, individual behaviors (e.g., drinking and screen time) warrant heightened attention in interventions targeting the reduction of depression in this population.
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Depressão , Exercício Físico , Humanos , Adolescente , Depressão/epidemiologia , Depressão/diagnóstico , Estudos de Coortes , Estudos Prospectivos , EstudantesRESUMO
Soil moisture flash drought can cause extensive damage to agriculture, ecosystems, and economies due to its sudden onset. Previous research identified soil moisture flash drought using stationary methods, in which, stationary probability distributions were employed to derive cumulative percentages (CPs) of given soil moisture values, and then based on the CPs sequence, the run theory was used to identify soil moisture flash drought events. However, because changes in climate or land cover can induce significant variations in the underlying probability distributions of soil moisture, the method's usual assumption of stationarity should be questioned. In this study, a nonstationary framework based on the nonstationary frequency analysis method and the run theory was developed for identifying soil moisture flash drought events. This framework was applied to the study of the pentad average root-zone soil moisture (PRZSM) of the Pearl River basin (PRB) in South China based on the ERA5-Land and the GLEAM datasets from 1981 to 2020. The results of the ERA5-Land were general consistent with those of the GLEAM, and the major findings include: (1) without considering the nonstationarity of soil moisture, the onset rate of flash droughts may be underestimated. The average onset rate of flash droughts in nonstationary conditions is slightly greater by 1 %/pentad -2 %/pentad than that in stationary conditions; (2) without considering the nonstationarity of soil moisture, the severity of flash droughts may be overestimated. The average severity of flash droughts in nonstationary conditions is smaller by 10% â pentads-20% â pentads than that in stationary conditions; and (3) the trends of the characteristics of soil moisture flash drought are consistent between the stationary and the nonstationary conditions. In conclusion, the above findings contribute to a better understanding of the implications of soil moisture nonstationarity on flash drought identification.
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Secas , Solo , Ecossistema , Clima , Rios , Mudança ClimáticaRESUMO
BACKGROUND: Previous studies have separately linked either perfluoroalkyl acid (PFAA) or heavy metal exposure with kidney dysfunction. However, the relationships of co-exposure to PFAAs and heavy metals with kidney function are still unclear. OBJECTIVES: To explore the associations between exposure to PFAAs and heavy metals mixtures and kidney function in adults. METHODS: We conducted a cross-sectional community-based population study in Guangzhou, China, enrolling 1312 adults from November 2018 to August 2019. We quantified 13 PFAAs in serum and 14 heavy metals in plasma. We chose estimated glomerular filtration rate (eGFR) and chronic kidney disease (CKD) as outcomes of interest. Distributed lag non-linear models (DLNMs) were used to check nonlinearity of individual pollutant with kidney function. Joint associations of pollutant mixtures on kidney function were assessed by Bayesian Kernel Machine Regression (BKMR) models. We further explored modification effects of gender. RESULTS: Most individual PFAA and heavy metal were associated with declined kidney function in single-pollutant models. We also observed significant dose-response relationships of pollutant mixtures with reduced eGFR levels and increased odds of CKD in BKMR models. Perfluoroheptanesulfonic acid (PFHpS), arsenic (As) and strontium (Sr) were the predominant contributors among pollutant mixtures. A change in log PFHpS, As and Sr concentrations from the 25th to the 75th percentile were associated with a decrease in eGFR of -5.42 (95% confidence interval (CI): -6.86, -3.98), -2.14 (95% CI: -3.70, -0.58) and -1.87 (95% CI: -3.03, -0.72) mL/min/1.73 m2, respectively, when other pollutants were at their median values. In addition, the observed associations were more obvious in females. CONCLUSIONS: We provided new evidence that co-exposure to PFAAs and heavy metals mixtures was associated with reduced kidney function in adults and PFHpS, As and Sr appeared to be the major contributors. Further studies are warranted to confirm our findings and elucidate the underlying mechanisms.
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Arsênio , Poluentes Ambientais , Fluorocarbonos , Metais Pesados , Insuficiência Renal Crônica , Adulto , Teorema de Bayes , China/epidemiologia , Estudos Transversais , Feminino , Humanos , Rim , Insuficiência Renal Crônica/induzido quimicamente , Insuficiência Renal Crônica/epidemiologia , EstrôncioRESUMO
Land-use/cover change (LUCC) is an important driver of environmental change, occurring at the same time as, and often interacting with, global climate change. Reforestation and deforestation have been critical aspects of LUCC over the past two centuries and are widely studied for their potential to perturb the global carbon cycle. More recently, there has been keen interest in understanding the extent to which reforestation affects terrestrial energy cycling and thus surface temperature directly by altering surface physical properties (e.g., albedo and emissivity) and land-atmosphere energy exchange. The impacts of reforestation on land surface temperature and their mechanisms are relatively well understood in tropical and boreal climates, but the effects of reforestation on warming and/or cooling in temperate zones are less certain. This study is designed to elucidate the biophysical mechanisms that link land cover and surface temperature in temperate ecosystems. To achieve this goal, we used data from six paired eddy-covariance towers over co-located forests and grasslands in the temperate eastern United States, where radiation components, latent and sensible heat fluxes, and meteorological conditions were measured. The results show that, at the annual time scale, the surface of the forests is 1-2°C cooler than grasslands, indicating a substantial cooling effect of reforestation. The enhanced latent and sensible heat fluxes of forests have an average cooling effect of -2.5°C, which offsets the net warming effect (+1.5°C) of albedo warming (+2.3°C) and emissivity cooling effect (-0.8°C) associated with surface properties. Additional daytime cooling over forests is driven by local feedbacks to incoming radiation. We further show that the forest cooling effect is most pronounced when land surface temperature is higher, often exceeding -5°C. Our results contribute important observational evidence that reforestation in the temperate zone offers opportunities for local climate mitigation and adaptation.
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Ecossistema , Florestas , Atmosfera , Mudança Climática , TemperaturaRESUMO
BACKGROUND: Analyses of the effects of pit and fissure sealant have been based on small samples and lack large-scale field evaluation data in China. The aim of this study was to understand the effect of pit and fissure sealant in preventing caries in the first permanent molars (FPMs) of children in Guangzhou. METHODS: We conducted a population-based cohort study using the database of the pit and fissure sealant program of Guangzhou. The carious status and sealant retention of the FPMs were assessed in 4,822 school children who received pit and fissure sealant 3 years prior to the study. The control group included 4,396 children who had indications for receiving pit and fissure sealant but were not treated and were matched according to sex, age and school. RESULTS: In the sealant group, the rate of sealant retention in the FPMs was 72.2%. Children in the sealant group had a 37% decreased risk of dental caries compared with the control group (adjusted HR = 0.63 [95% confidence interval (CI), 0.57-0.69], P < 0.001). Compared to no sealant use, the use of pit and fissure sealants reduced the risk of developing dental caries by 44% after 3 years in the FPMs of children from rural areas, reflecting a greater reduction than that among urban children (35%) during the same period (urban: adjusted hazard ratio (HR) = 0.65 [95% CI, 0.58-0.72]; rural: adjusted HR = 0.56 [95% CI, 0.45-0.70], P < 0.001). The mean number of decayed, missing, or filled permanent teeth (DMFT) in the control group was higher than that in the sealant group, and the difference was statistically significant regardless of sex. CONCLUSIONS: Pit and fissure sealant has a significant preventive effect against dental caries in the FPMs, especially for children in rural areas; thus, this sealant represents an effective technique for preventing and controlling dental caries.
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Cárie Dentária/terapia , Selantes de Fossas e Fissuras , Criança , China , Estudos de Coortes , Humanos , Dente MolarRESUMO
BACKGROUND: The relationship between body dissatisfaction (BD) and health-related quality of life (HRQoL) has been well documented in adolescents and adults but is less clear in children, particularly in China. The aims of this study were to describe body image perception and dissatisfaction and to examine their effects on HRQoL among primary school students in Guangzhou, China. METHODS: A total of 5734 children aged 8-12 years from 29 schools completed self-report questionnaires, which included the Paediatric Quality of Life Inventory 4.0 for measuring HRQoL and Ma figural stimuli for measuring BD. Based on their level of BD, the children were divided into three groups: no dissatisfaction, mild dissatisfaction and moderate or high dissatisfaction. Based on the children's perceptions of their own body image, the groups were also categorized into just right, too fat and too thin groups. Height and weight were objectively measured using standardized methods, and a BMI z-score was derived using the age- and sex-specific WHO references from 2007 for children aged 5-19 years. Weight status was classified as underweight, healthy weight, overweight or obese. RESULTS: A total of 78.10% of children aged 8-12 years in Guangzhou had different levels of BD; boys had slightly higher levels BD than girls (p < 0.01), and obese children demonstrated the highest degree of BD (p < 0.01). However, BD levels did not differ significantly according to age (p = 0.194). Gender differences in body image perceptions were only found in children with a healthy weight (p < 0.01), but age differences in body image perception were present in both children with a healthy weight (p < 0.05) and underweight children (p < 0.05). Of the children with a healthy weight who were dissatisfied with their body image, 65.54% of the boys wanted to be heavier, whereas 52.95% of the girls wanted to be thinner (p < 0.01), and older children were more inclined to perceive themselves as too fat (p < 0.01). After controlling for the influence of confounding factors, significant trends for lower HRQoL scores with increasing BD levels persisted in all domains (p < 0.01). CONCLUSIONS: BD is as common in children as in adolescents and adults and might be independently associated with HRQoL impairment. The present findings suggest that the current epidemic of BD is a threat to the health of primary school children in China, and prevention programmes for this population should be implemented in the future.
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Imagem Corporal/psicologia , Peso Corporal , Qualidade de Vida/psicologia , Fatores Etários , Índice de Massa Corporal , Criança , China/epidemiologia , Emoções , Feminino , Humanos , Masculino , Obesidade/psicologia , Prevalência , Autorrelato , Fatores Sexuais , Inquéritos e QuestionáriosRESUMO
Uncertainty is recognized as a critical consideration for accurately predicting stream water nitrogen (N) loading, but identifying the relative contribution of individual uncertainty sources within the total uncertainty remains unclear. In this study, a powerful method, referred to as the Bayesian inference combined with analysis of variance (BayeANOVA) was adopted to detect the timing and magnitude of multiple uncertainty sources and their relative contributions to total uncertainty in simulating daily loadings of three stream water N species (ammonium-N: NH4+-N, nitrate-N: NO3--N and total N: TN) in a rice agricultural watershed (the Tuojia watershed) as influenced by non-point source N pollution. Five sources of uncertainty have been analyzed in this study, which arise from model structure, parameters, inputs, interaction effects between parameters and inputs, and internal variability (induced by random errors of model or environment). The results show that uncertainty in parameters relating to the processes of both N and hydrologic cycles contributed the largest fractions of total uncertainty in N loading simulations (58.83%, 63.48% and 61.64% for NH4+-N, NO3--N and TN loading, respectively). Additionally, three of the largest uncertainties (i.e. parameters, inputs and interaction effects) in all three simulated N loadings were on average significantly greater in the rice-growing season relative to the fallow season, primarily due to the excess fertilization application during the rice-growing season. The predicted TN uncertainty was mainly attributed to the inaccuracy of NO3--N simulation, which contributed to 75.48% of predicted TN uncertainty. It is concluded that reducing the parameter uncertainty of NO3--N loading simulation during the rice-growing season is the key factor to improving stream water N modeling precision in rice agricultural watersheds.
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BACKGROUND: To investigate the association between weight status and health-related quality of life (HRQOL) among pupils in Guangzhou, China. METHODS: The study comprised 5781 children aged 8-12 years from 29 schools. Height and weight were objectively measured using standardized methods, and BMI z-score derived using the age and sex specific WHO reference 2007 for 5-19 years. Weight status was classified as underweight (<-2SD), healthy weight (between -2SD and 1SD), overweight/obesity (>1SD). HRQOL was measured by the self-report version of the Pediatric Quality of Life Inventory 4.0. RESULTS: After controlling for gender, age, school type, parental education, and family income, HRQOL scores were significantly lower in overweight/obese compared with healthy weight children only in the social functioning domain (ß = -1.93, p = 0.001). Compared with healthy weight children, underweight children had significantly lower total (ß = -1.47, p = 0.05) and physical summary scores (ß = -2.18, p = 0.02). Subgroup analysis for gender indicated that compared to healthy weight, total (ß = -1.96, p = 0.02), psychosocial (ß = -2.40, p = 0.01), social functioning (ß = -3.36, p = 0.001), and school functioning (ß = -2.19, p = 0.03) scores were lower in overweight/obese girls, but not boys. On the other hand, being underweight was associated with lower physical functioning (ß = -2.27, p = 0.047) in girls, and lower social functioning (ß = -3.63, p = 0.01) in boys. The associations were mainly observed in children aged 10 and over, but were not significant in younger children. Children from private schools had generally lower HRQOL compared to those in public schools, but the associations with weight status were similar in both groups. CONCLUSIONS: The relationship between overweight/obesity and HRQOL in children in China is not as prominent as that seen in children in western or high-income countries. However, there appears to be gender and age differences, with more of an impact of overweight on HRQOL in girls and older children compared with boys and younger children. Underweight is also associated with lower HRQOL. Future intervention to prevent both obesity and undernutrition may have a positive impact on the HRQOL in children in China.
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Obesidade Infantil/epidemiologia , Qualidade de Vida , Índice de Massa Corporal , Peso Corporal , Criança , Serviços de Saúde da Criança , China/epidemiologia , Estudos Transversais , Feminino , Indicadores Básicos de Saúde , Humanos , Masculino , Pais/psicologia , Obesidade Infantil/etiologia , Obesidade Infantil/psicologia , Serviços de Saúde Escolar , Instituições AcadêmicasRESUMO
Meckel-Gruber syndrome (MKS) is a lethal autosomal recessive condition characterized by renal cysts and variably associated features, including developmental anomalies of the central nervous system (typically encephalocele), hepatic ductal dysplasia and cysts, and polydactyly. Genetic heterogeneity has been demonstrated at eleven loci, MKS1-11. Here, we present the clinical and molecular characteristics of a Chinese MKS3 family with occipital encephalocele and kidney enlargement. DNA sequencing of affected fetuses revealed a homozygous c.1645C>T substitution in exon 16 of TMEM67, leading to a p.R549C substitution in meckelin. The R549 residue is highly conserved across human, rat, mouse, zebrafish, chicken, wolf and platypus genomes. Hha I restriction analysis demonstrated that the c.1645C>T mutation was absent in 200 unrelated control chromosomes of Chinese background, supporting the hypothesis that it represents causative mutation, not rare polymorphism. Our data provide additional molecular and clinical information for establishing a better genotype-phenotype understanding of MKS.
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Transtornos da Motilidade Ciliar/genética , Encefalocele/genética , Proteínas de Membrana/genética , Mutação de Sentido Incorreto , Doenças Renais Policísticas/genética , Anormalidades Múltiplas/genética , China , Análise Mutacional de DNA , Família , HumanosRESUMO
The principles and degrees to which land use change and climate change affect direct runoff generation are distinctive. In this paper, based on the MODIS data of land use in 1992 and 2003, the impacts of land use and climate change are explored using the Soil Conservation Service Curve Number (SCS-CN) method under two defined scenarios. In the first scenario, the precipitation is assumed to be constant, and thus the consequence of land use change could be evaluated. In the second scenario, the condition of land use is assumed to be constant, so the influence only induced by climate change could be assessed. Combining the conclusions of two scenarios, the effects of land use and climate change on direct runoff volume can be separated. At last, it is concluded: for the study basin, the land use types which have the greatest effect on direct runoff generation are agricultural land and water body. For the big sub basins, the effect of land use change is generally larger than that of climate change; for middle and small sub basins, most of them suffer more from land use change than from climate change.
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Mudança Climática , Ecossistema , Chuva/química , Rios/química , Agricultura , China , Reforma UrbanaRESUMO
Time-varying moments models based on Pearson Type III and normal distributions respectively are built under the generalized additive model in location, scale and shape (GAMLSS) framework to analyze the nonstationarity of the annual runoff series of the Weihe River, the largest tributary of the Yellow River. The detection of nonstationarities in hydrological time series (annual runoff, precipitation and temperature) from 1960 to 2009 is carried out using a GAMLSS model, and then the covariate analysis for the annual runoff series is implemented with GAMLSS. Finally, the attribution of each covariate to the nonstationarity of annual runoff is analyzed quantitatively. The results demonstrate that (1) obvious change-points exist in all three hydrological series, (2) precipitation, temperature and irrigated area are all significant covariates of the annual runoff series, and (3) temperature increase plays the main role in leading to the reduction of the annual runoff series in the study basin, followed by the decrease of precipitation and the increase of irrigated area.
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Modelos Teóricos , Rios , Movimentos da Água , Abastecimento de Água , China , Clima , Hidrologia , Chuva , TemperaturaRESUMO
Three different hydrological models are chosen to simulate rainfall-runoff relationships under each of three objective functions including mean squared errors of squared transformed flows, squared root transformed flows and logarithmic transformed flows; thus nine individual models are constructed. By weighted averaging over these nine models, the method of Bayesian model averaging (BMA) was used to provide both the mean value and the uncertainty intervals of flow prediction. Three kinds of uncertainty information can be generated: the uncertainty of individual member model's predictions; the total uncertainty of BMA mean prediction; the between-model and within-model uncertainties in the BMA scheme. Based on the estimated results in this study, the coupling of multiple models with multiple objective functions in general offers better results for both the mean prediction and the uncertainty intervals for the runoffs in a selected basin in Han River, China, than the individual models.
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Hidrologia/métodos , Modelos Teóricos , Rios , Movimentos da Água , Teorema de Bayes , ChinaRESUMO
A chiral heteometallic compound, [(EMIM)NaCu(1,4-ndc)2]n (1), constructed from the achiral 1,4-naphthalenedicarboxylate (1,4-ndc) ligand has been ionothermally synthesized and structurally and magnetically characterized. The chiral induction effect of the enantiopure 1-ethyl-3-methylimidazolium (EMIM) L-lactate additive in the ionothermal reaction is briefly discussed.
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BACKGROUND: Some reports suggest mesenchymal stem cells (MSCs) have immunosuppressive properties. However, conflicting evidence regarding the role of MSCs has emerged. OBJECTIVES: To gain a better understanding of the immunosuppressive properties of mesenchymal stem cells (MSCs) in a rat heart transplantation model. MATERIAL AND METHODS: MSCs were obtained from the femoral and tibial bone marrow of Sprague-Dawley rats and cultured. Heart-transplanted rats were allocated into a MSC-treated group and 2 control groups. On postoperative day 7, 1 rat was sacrificed and the pathological changes of heart tissues were assessed. Serum proteomic spectra were generated by surface-enhanced laser desorption/ionization-time-of-flight mass spectrometry (SELDI-TOF-MS). RESULTS: Rat MSCs displayed the typical spindle-shaped morphology in culture and significantly prolonged the graft survival up to 33.25 ± 2.54 days compared with controls (19.75 ± 1.56 and 11.16 ± 1.34 days, respectively). Pathological analysis showed the inflammatory cell infiltration in the MSC-treated group was significantly reduced. SELDI analysis showed that 5 protein/peptide peaks with M/Z 1272.33, 1986.65, 2323.42, 5375.59 and 12968.11 were up-regulated in the MSC-treated group (P < 0.001). CONCLUSIONS: Donor-derived MSCs clearly alleviate acute rejection following heart transplantation in rats and significantly prolong the isograft survival time.
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Transplante de Coração , Terapia de Imunossupressão , Transplante de Células-Tronco Mesenquimais , Proteômica/métodos , Animais , Proteínas Sanguíneas/análise , Modelos Animais de Doenças , Masculino , Miocárdio/patologia , Ratos , Ratos Sprague-Dawley , Ratos Wistar , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Transplante HomólogoRESUMO
BACKGROUND: Methylation of human tissue factor pathway inhibitor-2 (TFPI-2) gene has been detected in several types of cancer, including non-small cell lung cancer (NSCLC). However, an association between the methylation status of TFPI-2 gene and prognosis has not yet been investigated. METHODS: Methylation of TFPI-2 gene was examined in a consecutive series of 133 non-metastatic NSCLC patients using methylation-specific PCR (MSP). Univariate and multivariate analyses were conducted to investigate the association between clinical variables and overall survival time. RESULTS: Methylation of TFPI-2 gene was detected in 36 of 133 patients (27.1%). Of these 36 patients, seventeen individuals (47.2%) carried stage III tumors. The 5-year disease free survival rate among patients carrying methylated TFPI-2 tumors was significantly lower as compared to those with unmethylated TFPI-2 tumors (35.5% versus 6.1%, P<0.0001). Moreover, methylation of TFPI-2 gene was found to be an independent prognostic factor for poor overall survival based on multivariate analysis models (P=0.013), as was age >62 years old (P<0.0001) and TNM stage of disease (P<0.0001). CONCLUSIONS: The results of the present study suggest that methylation of TFPI-2 gene is an independent factor for an unfavorable prognosis in patients with NSCLC.
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Adenocarcinoma/genética , Carcinoma de Células Grandes/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma de Células Escamosas/genética , Metilação de DNA , Glicoproteínas/genética , Neoplasias Pulmonares/genética , Adenocarcinoma/mortalidade , Adenocarcinoma/patologia , Carcinoma de Células Grandes/mortalidade , Carcinoma de Células Grandes/patologia , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , DNA de Neoplasias/genética , Feminino , Seguimentos , Humanos , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , RNA Neoplásico/genética , Reação em Cadeia da Polimerase em Tempo Real , Taxa de SobrevidaRESUMO
A novel method for the simultaneous determination of imperatorin and isoimperatorin in cosmetics by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was developed. The imperatorin and isoimperatorin were extracted by methanol. The analytes were separated on a C18 column using 10 mmol/L ammonium acetate/ methanol-5 mmol/L ammonium acetate aqueous solution (80:20, v/v) as mobile phase, and then detected by HPLC-MS/MS using multiple reaction monitoring (MRM) mode. The good linearities (r > 0.999) were achieved for the target compounds over the range of 0.25-20 microg/L. The limits of quantification (LOQs) were 0.5 mg/kg. The recoveries for the imperatorin and isoimperatorin varied from 82.2% to 105% and 80.0% to 103% with the relative standard deviations ranging from 2.7% to 4.9% and 1.8% to 4.6% respectively in the range of 0.50-10.0 mg/kg. The method can meet the requirements for the simultaneous determination of imperatorin and isoimperatorin in cosmetics.